Wi-Fi may be implemented with a limited amount of frequency resources that use techniques of collision avoidance to allow multiple user equipments (UE's) to share the same channel. As the numbers of UE's increase, the impact of collision avoidance restricts the ability of co-located Cellular Base Stations (BTS) or Wi-Fi access points (AP) to support many users without impacting the performance to and from each UE. Co-located AP's, otherwise known as multi-beam access points (MBAP's), may include a group of AP's with the ability to serve different UE's on the same frequency using directive signal beamformers with multi-beam antennas. However, several limitations of Wi-Fi multi-beam antennas may need to be addressed in order to provide signals to multiple UE's on the same frequency. First, since WiFi is a time division multiplex system (TDD), the transmitting and receiving functions may use the same channel. Unsynchronized operation between APs means a transmitting AP's signal may interfere with the reception of another AP that uses the same channel unless sufficient isolation (e.g., 125 dB) is provided between the transmitting and receiving functions.
Some solutions for providing sufficient isolation may involve using physically separated antenna arrays for transmit and receive functions. Other solutions may provide cancellation of each transmitted signal within the receiver processing functions. Another limitation of multi-beam antennas is that they may not offer complete separation of coverage from one beam to other adjacent beams. Systems and methods may be needed to mitigate the performance effects of overlapping beams of adjacent antennas. In addition to overlapping beams, sidelobe radiation from a beam may introduce extraneous radiation in other beams, causing further interference.